Physicochemical Characterization of a Fern Polysaccharide from Alsophila spinulosa Leaf and Its Anti-Aging Activity in Caenorhabditis elegans.

Alsophila spinulosa, as a rare tree fern with potential medicinal value, has attracted extensive attention. Herein, the physicochemical properties, antioxidant and anti-aging activities of polysaccharide from A. spinulosa leaf (ALP) were investigated. ALP was composed of galactose, arabinose, glucose, rhamnose, galacturonic acid, mannose, and fucose. (1→), (1→6), and (1→2) bond types were the primary glycosidic bond in ALP. Surprisingly, ALP displayed the wonderful activity of antioxidant and anti-aging, including excellent scavenging ability against DPPH and ABTS radicals in vitro; prolonging the life span, improving activity of antioxidative enzymes (SOD and CAT), and decreasing the level of ROS, MDA in Caenorhabditis elegans. Meanwhile, ALP promoted DAF-16 to move into the nuclear. Overall, our results illustrated that ALP could be further developed as a functional food ingredient.